Unicompartmental (Partial) Knee Replacement

Unicompartmental knee replacement (UKR) is considered when osteoarthritis is limited to only one compartment of the knee. Instead of reshaping the entire joint, only the worn portion is replaced using metal and plastic components, allowing the remaining healthy cartilage and bone to remain untouched.

Who Should Not Have UKR

Some individuals are not ideal candidates:

  • Obesity

  • Inflammatory arthritis (e.g., rheumatoid arthritis)

  • Torn or deficient cruciate ligaments

  • Significant stiffness or bowed knee

  • Arthritis affecting more than one compartment (exceptions may exist for symptom-free patellofemoral arthritis)

Advantages of UKR

Patients often appreciate:

  • Faster recovery

  • Less discomfort due to smaller incision and less soft-tissue trauma

  • Reduced blood loss

  • Potentially better knee movement

  • A knee that feels more “natural” because cruciate ligaments are preserved

Disadvantages of UKR

  • Outcomes may be less predictable compared to total knee replacement

  • Arthritis may progress over time, possibly requiring further surgery

Total Knee Replacement (TKR)

For those with widespread arthritis affecting the entire knee, total knee replacement offers reliable pain relief and significantly improves mobility and quality of life. There are no strict limits based on age or body weight. Decisions depend mainly on levels of pain and disability.

Patients of all ages—from teenagers with juvenile arthritis to elderly individuals with degenerative wear—may undergo TKR successfully.

Before Surgery

A comprehensive medical evaluation is performed beforehand, including:

  • Blood and urine tests

  • ECG

  • Additional tests depending on overall health

Patients may be admitted a day before surgery or even on the same day. The anesthetist will discuss anesthesia options and involve the patient in choosing the most suitable approach.

During and Immediately After Surgery

The operation itself usually takes 1–2 hours, followed by observation in the recovery area.
Hospital stay typically lasts 3–7 days, during which:

  • Pain control is a priority

  • Physiotherapists help with early knee mobilisation and teach exercises

  • Patients practice walking aids like crutches or a frame

Recovery at Home

Once discharged, regular exercises remain essential.

  • Stitches or clips are removed around 10–14 days

  • Over 4–6 weeks, walking often becomes easier and aids can be reduced

  • Around 90° of knee bend is expected by 6 weeks; if not, manipulation under anesthesia may be needed

During this period, patients must monitor for:

  • Calf pain or swelling (possible clot)

  • Increased redness, fever, or discharge (possible infection)
    Immediate medical attention is advised if these occur.

Long-Term Expectations

Improvements continue for 1–2 years after surgery. Swelling may take 6–12 months to resolve. Modern knee replacements have excellent longevity—over 90% remain functional 15 years after implantation.

As with any joint, a replacement can eventually wear out or loosen, sometimes requiring revision surgery. Following the surgeon’s guidance, maintaining joint health, and being mindful of overall wellness all play a role in long-term success.